1840:
January 10: Penny postage introduced in Great Britain
February 10: Queen Victoria of England marries Prince Albert of Saxe Coburg-Gotha.
May 1: The first postage stamps, Britain’s “Penny Black,” is issued.
Summer/Fall: The 1840 presidential campaign is the first to prominently feature songs and slogans. William Henry Harrison wins the presidency thanks to his “Log Cabin and Hard Cider” campaign, and the slogan “Tippecanoe and Tyler Too!”
1841:
March 4: William Henry Harrison is inaugurated as US president and delivers a two-hour inaugural address in cold weather. He catches pneumonia, from which he never recovers.
April 4: Death of American president William Henry Harrison after only one month in office. He is the first American president to die in office, and is succeeded by the vice-president, John Tyler.
November 9: Birth of Edward VII of England, son of Queen Victoria and Prince Albert.
1842:
January: The British retreat from Kabul, Afghanistan and are massacred by Afghan troops.
August 29: First Opium War ends with Treaty of Nanking.
1843:
February: First minstrel show held in New York City.
Summer: With "Oregon Fever" gripping America, 1843 marks the beginning of mass migration westward on the Oregon Trail.
1844:
February 28: Accident with cannon on US Navy warship kills two members of John Tyler’s cabinet.
May 24: First telegram sent from US Capitol to Baltimore. Samuel F.B. Morse writes, “What hath God wrought.”
August: Karl Marx and Friedrich Engels meet in Paris
October 15: Birth of philosopher Friedrich Nietzsche in Germany.
November: James Knox Polk defeats Henry Clay in US presidential election.
1845:
January 23: US Congress establishes a uniform date for federal elections, which shall be the first Tuesday after the first Monday in November.
March 1: President John Tyler signs bill annexing Texas.
March 4: James Knox Polk inaugurated as US President.
May: Frederick Douglass publishes his autobiography, Narrative of the Life of Frederick Douglass, An American Slave.
May 20: The Franklin Expedition sets sail from Britain.
Late Summer: The Irish potato famine, which will become known as The Great Famine, begins with widespread failures of the potato crop.
1846:
February 26: Birth of American frontier scout and showman William F. “Buffalo Bill” Cody.
April 25: Mexican troops ambush and kill a patrol of US soldiers. Reports of the incident inflame tensions between the two nations.
April-August: Francis Parkman travels from St. Louis, Missouri to Ft. Laramie, Wyoming, and later writes about it in the classic book, The Oregon Trail.
May 13: US Congress declares war against Mexico.
June 14: Bear Flag Revolt, settlers in northern California declare independence from Mexico.
December: The Donner Party, a party of American settlers in wagon trains, is stranded in the snow-covered Sierra Nevada Mountains in California and begins to resort to cannibalism to survive.
1847:
February 22: Battle of Buena Vista in the Mexican War. US troops under General Zachary Taylor defeat a Mexican army.
March 29: US troops commanded by General Winfield Scott capture Veracruz.
Late summer: The potato famine continues in Ireland, reaching a peak in this year, which becomes known as “Black 47.”
September 13-14: US troops enter Mexico City, effectively bringing and end to the Mexican War.
December 6, 1847: Abraham Lincoln takes his seat in the US House of Representatives. He would serve a single two-year term before returning to Illinois.
1848
January 24, 1848: James Marshall, a mechanic working at John Sutter's sawmill in northern California, recognizes some unusual nuggets, and his discovery will set off the California Gold Rush.
March 23, 1848: Former president John Quincy Adams, who went on to serve in Congress after leaving the presidency, dies after collapsing in the US Capitol building.
July 12-19: Conference at Seneca Falls, New York, organized by Lucretia Mott and Elizbeth Cady Stanton takes up the issue of Women's Rights, and plants the seeds of the suffrage movement in the US.
November 7: Zachary Taylor, Whig candidate and a hero of the Mexican War, is elected president of the US.
December 5: President James Knox Polk, in his annual address to Congress, confirms the discovery of gold in California.
1849
March 5: Zachary Taylor is inaugurated as the 12th president of the US. He is the third, and last, candidate of the Whig Party to hold the office.
